Stop TB Partnership

South African Study Provides Compelling New Evidence on Role of Person to Person Transmission in Drug-Resistant TB Epidemics


Emory/CDC/NIH study published in The New England Journal of Medicine adds to growing body of evidence that extensively drug-resistant TB is fueled more by direct transmission than previously thought in high-burden settings.

19 January 2017, KwaZulu-Natal, South Africa - A study published this week in The New England Journal of Medicine provides compelling evidence that extensively drug-resistant (XDR) TB is spreading from person-to-person in KwaZulu-Natal, South Africa. The study builds on a growing body of evidence showing that direct transmission is driving the spread of drug-resistant TB in some countries with high burden of disease. The study was funded by the National Institutes of Health and led by Dr. Sarita Shah of CDC’s Division of Global HIV & TB and Dr. Neel R. Gandhi of Emory University as well as researchers from Albert Einstein College of Medicine, and the University of KwaZulu Natal in South Africa.

This analysis found that the majority of cases (69 percent) in KwaZulu Natal, South Africa occurred as a result of person-to-person transmission rather than inadequate TB treatment. It identified epidemiologic links between 30 percent of participants, with many connected through hospitals, households, and community settings, such as workplaces. The study has important implications for prevention and treatment efforts for XDR TB.

XDR TB is a global epidemic. Reported in 105 countries worldwide, XDR TB is resistant to at least four of the best anti-TB drugs. In most places, treatment of XDR TB is successful less than 40 percent of the time, with death rates as high as 80 percent for patients who also have HIV.

"These findings are further proof that we need to better detect, prevent, diagnose, and treat drug-resistant TB," said CDC Director Tom Frieden, M.D., M.P.H. "TB resistant to last-resort drugs is spreading through hospitals and homes, at work, and in other places in this high burden community. The only way to stop this disease is by improving infection control and rapidly finding and effectively treating people with TB."

Study authors suggest that breaking the cycle of transmission of drug-resistant TB requires a greater focus on infection control efforts - while also maintaining global programs to quickly detect and effectively treat all people with TB.

CDC’s Division of Global HIV & TB (DGHT) is working to find, cure, and prevent TB worldwide, through on-the-ground interventions in more than 25 countries and global leadership in research and technical expertise.

Learn More & Share:

  • Learn more about CDC’s efforts around this study here.
  • Read the full New England Journal of Medicine article here
  • Learn more about the urgent threat of drug-resistant TB
  • Read how one CDC expert is fighting XDR TB around the world
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